Hi, I have a small patio on the north side of my house. It is concrete with bricks set on edge throughout the patio. Over the years the bricks have broken apart, so now I have unsightly holes where the bricks were. I live at 5,000' where it can get close to zero in the winter. When it snows, this little patio usually doesn't get shoveled and can end up under a layer of ice for a few weeks - but it can also get to 100 in the summer.

I'd like to plant a hardy ground cover in the holes. Something that can be walked on, that will survive full shade and cold temps. I've tried moss in the past, but it doesn't survive.

Any suggestions? Thanks.